Caramelised Onion Soup With Gruyere

by Susan Smith in , ,

Who can resist a simple, savoury broth with melting cheese? Not me! Last week Sarah succumbed to a nasty cold virus so I upped the ante on her intake of vitamins and minerals by replacing our usual pre-dinner glass of wine with either a green smoothie or a comforting bowl of fresh vegetable soup.

Sarah was never a big fan of onion soup until I persuaded her to try this healthy, restorative, Primal variation of traditional French onion soup - no crouton, but still lots of cheese on top of caramelised onions sat in a deeply flavoured golden broth, with just a touch of apple brandy for medicinal purposes. Good call! I told Sarah there is great healing power in onions (it’s true!), though neither of us are willing to eat our onions raw and I think she would have definitely drawn the line at using halved raw onions as air purifiers (reputedly, they kill off airborne germs/bacteria), or more bizarrely, sticking one inside her sock at night to pull the toxins from her body to help her heal! Instead, I settled on making her this delicious soup. 

Apart from slicing what seems to be a copious amount of onions - trust me, four large onions isn’t too many because they melt down to a quarter of their original volume during cooking - there’s very little ‘hands-on’ time involved in making this soup. True, it can take up to 45 minutes of slowly, slowly sweating the onions down in butter to tease out their natural sweetness and to caramelise them into a deep mahogany-brown, meltingly-soft conglomeration of intensely flavoured oniony goodness but, apart from the occasional stir, they can be more or less left alone to do their thing whilst you attend to other matters.  

Caramelised Onion Soup With Gruyere is much healthier than French onion soup because it doesn’t have the classic bread crouton submerged in it. And, whether you’re feeling under the weather or not, it’s also a lot easier to eat when you don’t have to chase unwieldy pieces of soggy bread around your bowl with a spoon! Tastewise, this simple yet sophisticated soup loses nothing in translation. Sweet, succulent and intensely umami, it’s a surefire recipe for success. 

So, don’t wait to catch a cold. This fabulous soup is a cheap, low-carb, health-boosting food that goes way beyond the curative powers of onions. Deeply flavoursome, without any of raw onion’s lingering pungency (I do so hate the smell of onion/garlic breath!), it’s a heart-warming bowl of soft, sweet loveliness incapable of offending anyone. What’s not to love? I hope you will enjoy it as much as Sarah did. 

Caramelised Onion Soup With Gruyere (Serves 4)


4 large organic onions, very finely sliced (I used this mandolin slicer - a bit more expensive to buy, but worth every penny)

50g organic unsalted butter

1 tsp organic raw coconut palm sugar

40ml Calvados (apple brandy)

1 litre well-flavoured stock 

1 bay leaf

2 tbsp fresh thyme, leaves only

1 tbsp organic tamari (I used Clearspring)

sea salt and freshly ground black pepper

handful of fresh parsley, very finely chopped - to serve

80g Gruyere, finely grated (or vegetarian alternative, see notes below)



Melt the butter in a large pan. Add the sliced onions, sprinkle over the coconut palm sugar and add a small pinch of sea salt. Stir well to ensure the onions are evenly doused in the butter, then cover with the pan lid and sweat down very gently over a low heat for 20-25 minutes, stirring occasionally, until the onions are soft and translucent, but not browned.

Turn the heat up to medium and continue cooking for a further 15-20 minutes, stirring from time to time, until the onions are deep golden-brown, caramelised and sticky.  

Turn the heat up to high. Add the apple brandy and continue cooking 1-2 minutes more until the liquid is reduced and the alcohol has evaporated. 

Pour in the stock then add the tamari, bay leaf and thyme and bring to the boil. Check the seasoning, adding a little more sea salt, if required.

As soon as the broth has reached boiling point, turn the heat down to low and simmer the soup, uncovered, for 20 minutes. At the end of the cooking time, discard the bay leaf.

Ladle the onion soup into four pre-warmed bowls, dividing it equally between them. 

Sprinkle with the grated Gruyere and finish with a grinding of black pepper and the chopped parsley. Serve piping hot. 



The stock I used on this occasion was a nutritious, homemade chicken bone broth made from the carcass of an organic chicken I’d previously cut up to make pet food for my cat Sushi. Waste not, want not! However, if you’re strictly vegetarian, or don’t have any bone broth, it will still taste good with a simple stock made from freshly filtered water and organic vegetable bouillon powder.

Gruyere D.O.P. is the preferred cheese for making the classic garnish of cheese-topped croutons for French onion soup for good reason - it melts beautifully and has a deep, intense, nutty flavour. For non-vegetarians, Gruyere is the perfect accompaniment to Caramelised Onion Soup. 

Followers of the Paleo diet will enjoy Caramelised Onion Soup without any cheese, whilst strict vegetarians will want to substitute a cheese that isn’t made with animal rennet. For vegetarians I recommend using tasty, tangy, Parmesan-style Gran Moravia or a strong-tasting, organic, vegetarian-friendly Cheddar instead of Gruyere. 


Carbohydrate 10g Protein 8g - per serving